The preparation of use of (hydrocarbonthio)oxamides as vulcanization retarders is disclosed in U.S. Pat. No. 3,780,001. In accordance with this patent the (hydrocarbonthio)oxamides are prepared by reaction between a hydrocarbon sulfenyl chloride and an oxamide or derivative thereof in the presence of certain solvents including alkyl hydrocarbons such as heptane and hexane, halogenated alkyls such as carbon tetrachloride, trichloromethane, methylene chloride, trichloroethane, aromatic hydrocarbons such as benzene, toluene and chlorobenzene, or tetrahydrofuran, dioxane and dimethyl formamide, preferably tetrahydrofuran or dimethyl formamide. An improved process for the preparation and recovery of these (hydrocarbonthio)oxamides is desired.